Sunday, April 26, 2009

Mexico City Is the Epicenter of a New Strain of Swine Flu

"Avian flu, which has killed 250 people since 2003 and sparked the last pandemic threat, is caused by influenza viruses adapted to infect birds. Swine flu is caused by viruses adapted to pigs. Big problems arise when human and animal flu viruses mix and mutate into new organisms that can spread through the population. [Search Google News for swine flu.]

The fact that most of the Mexican dead were aged between 25 and 45 rather than being elderly or very young is seen as a particularly worrying sign. The first victims of the Spanish flu pandemic of 1918 were also healthy young adults.[See Wikipedia on the 1918 Spanish Flu Pandemic.]

The symptoms of swine flu in people include fever, fatigue, lack of appetite, coughing and sore throat.

Michael Osterholm [search Google News], a pandemic flu expert at the University of Minnesota, said new cases were probably already incubating around the world.

Tamiflu, an antiviral drug used against bird flu, is said to be effective against the new strain."--The Times (4-26-09)

A new strain of swine flu--influenza strain A subtype H1N1--has appeared in Mexico City. Over 22 million people live in the greater metropolitan area of Mexico City. It is the largest metropolitan area in the western hemisphere and the second largest metropolitan area in the world. The Mexico City flu is reportedly a new combination of two strains of swine flu, a strain of human flu, and a strain of bird flu. These four strains of influenza viruses seem to have recombined in pigs to create a new virus.

In its entry on swine flu, Wikipedia comments:

Pigs can harbor influenza viruses adapted to humans and others that are adapted to birds, allowing the viruses to exchange genes and create a pandemic strain.

Pigs can transmit many diseases to humans and may even have been responsible for an epidemic that destroyed Indian civilizations in North America. Indian people did not live in close contact with farm animals and had no immunity to diseases that Old World people contracted from animals.

In his March 2002 Atlantic Monthly article "1491," Charles C. Mann writes [mirrored here]:

[T]he worst thing the Spaniards did, some researchers say, was entirely without malice—bring the pigs.

According to Charles Hudson, an anthropologist at the University of Georgia who spent fifteen years reconstructing the path of the expedition, Soto crossed the Mississippi a few miles downstream from the present site of Memphis. It was a nervous passage: the Spaniards were watched by several thousand Indian warriors. Utterly without fear, Soto brushed past the Indian force into what is now eastern Arkansas, through thickly settled land—"very well peopled with large towns," one of his men later recalled, "two or three of which were to be seen from one town." Eventually the Spaniards approached a cluster of small cities, each protected by earthen walls, sizeable moats, and deadeye archers. In his usual fashion, Soto brazenly marched in, stole food, and marched out.

After Soto left, no Europeans visited this part of the Mississippi Valley for more than a century. Early in 1682 whites appeared again, this time Frenchmen in canoes. One of them was Réné-Robert Cavelier, Sieur de la Salle. The French passed through the area where Soto had found cities cheek by jowl. It was deserted—La Salle didn't see an Indian village for 200 miles. About fifty settlements existed in this strip of the Mississippi when Soto showed up, according to Anne Ramenofsky, an anthropologist at the University of New Mexico. By La Salle's time the number had shrunk to perhaps ten, some probably inhabited by recent immigrants. Soto "had a privileged glimpse" of an Indian world, Hudson says. "The window opened and slammed shut. When the French came in and the record opened up again, it was a transformed reality. A civilization crumbled. The question is, how did this happen?"

The question is even more complex than it may seem. Disaster of this magnitude suggests epidemic disease. In the view of Ramenofsky and Patricia Galloway, an anthropologist at the University of Texas, the source of the contagion was very likely not Soto's army but its ambulatory meat locker: his 300 pigs. Soto's force itself was too small to be an effective biological weapon. Sicknesses like measles and smallpox would have burned through his 600 soldiers long before they reached the Mississippi. But the same would not have held true for the pigs, which multiplied rapidly and were able to transmit their diseases to wildlife in the surrounding forest. When human beings and domesticated animals live close together, they trade microbes with abandon. Over time mutation spawns new diseases: avian influenza becomes human influenza, bovine rinderpest becomes measles. Unlike Europeans, Indians did not live in close quarters with animals—they domesticated only the dog, the llama, the alpaca, the guinea pig, and, here and there, the turkey and the Muscovy duck. In some ways this is not surprising: the New World had fewer animal candidates for taming than the Old. Moreover, few Indians carry the gene that permits adults to digest lactose, a form of sugar abundant in milk. Non-milk-drinkers, one imagines, would be less likely to work at domesticating milk-giving animals. But this is guesswork. The fact is that what scientists call zoonotic disease was little known in the Americas. Swine alone can disseminate anthrax, brucellosis, leptospirosis, taeniasis, trichinosis, and tuberculosis. Pigs breed exuberantly and can transmit diseases to deer and turkeys. Only a few of Soto's pigs would have had to wander off to infect the forest.

[See Charles Mann's excellent March 2002 Atlantic Monthly article "1491" and read his book, 1491: New Revelations of the Americas Before Columbus.]

The Center for Disease Control (CDC) site has updates about this new strain of swine flu. Here is the CDC's Human Swine Flu Investigation site. Here is the Word Health Organization (WHO) site with updates about the swine influenza.

The CDC has a film that shows you how to wash your hands properly. Clean hands save lives! Perhaps 80% of infections are transmitted by our hands.


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